We now wish to define a notion of deformations of a para-complex structure, and study the integrability
of such deformations.
Notice that we explicitly distinguish deformations of the para-complex structure \(K\)  from
deformations of the para-Hermitian structure \((g,K)\) ; in the former, we only deal with
a family \(K(t)\)  of para-complex structures satisfying the para-Hermitian condition with
respect to some fixed metric \(g\) , while in the latter, one should consider families of both
para-complex structures \(K(t)\)  and metrics \(g(t)\) .
For the definition of deformations, we will follow [1]} and [2]}.
The setting in these works is however slightly different than ours in the sense that they consider deformations
of complex structures, where the eigenbundles are complex conjugates, whereas in our
case they are independent since we consider para-complex structures (or even complex-valued maps).
Our definition will agree with that of [3]}.
